Bearing cage and ball bearing

A bearing cage for a ball bearing, comprising:

• an annular backbone portion comprising a front side and an opposite back side;
• and
• a plurality of cantilever portions extending from the front side of the backbone portion in an axially forward direction of the bearing cage, the plurality of cantilever portions arranged along a circumference of the annular backbone portion and defining a plurality of pockets for accommodating one or more rolling elements of the ball bearing,
• wherein each of the plurality of cantilever portions comprises:
• two prong portions;
• a connection portion between the two prong portions, each of the prong portions comprises a contacting surface;
• and
• a plurality of grooves formed in a radially inner side of the bearing cage,
• wherein 0.3 mm≤S≤3.5 mm, and
• wherein S is a smallest distance between the contacting surface and the groove adjacent to the contacting surface.

A bearing cage for a ball bearing, comprising:

• an annular backbone portion comprising a front side and an opposite back side;
• and
• a plurality of cantilever portions extending from the front side of the backbone portion in an axially forward direction of the bearing cage, the plurality of cantilever portions arranged along a circumference of the annular backbone portion and defining a plurality of pockets for accommodating one or more rolling elements of the ball bearing,
• wherein each of the plurality of cantilever portions comprises:
• two prong portions;
• a connection portion between the two prong portions, each of the prong portions comprising a contacting surface;
• and
• a plurality of grooves formed in a radially inner side of the bearing cage,
• wherein 0.05*[(Dw*dc){circumflex over ( )}(⅓)]≤S≤0.3*[(Dw*dc){circumflex over ( )}(⅓)],
• wherein S is a smallest distance between the contacting surface and the groove adjacent to the contacting surface, Dw is a diameter of a rolling element of the one or more rolling elements, and dc is an inner diameter of the bearing cage.

A bearing cage for a ball bearing, comprising:

• an annular backbone portion comprising a front side and an opposite back side;
• and
• a plurality of cantilever portions extending from the front side of the backbone portion in an axially forward direction of the bearing cage, the plurality of cantilever portions arranged along a circumference of the annular backbone portion and defining a plurality of pockets for accommodating one or more rolling elements of the call bearing,
• wherein each of the plurality of cantilever portions comprises:
• two prong portions;
• a connection portion between the two prong portions;
• and
• a plurality of grooves formed in a radially inner side of the bearing cage,
• wherein 0.3 mm≤L5≤3 mm, and
• wherein L5 is a smallest distance between an edge of the groove and an end of the connection portion away from the backbone portion.

A bearing cage for a ball bearing, comprising:

• an annular backbone portion comprising a front side and an opposite back side;
• and
• a plurality of cantilever portions extending from the front side of the backbone portion in an axially forward direction of the bearing cage, the plurality of cantilever portions being arranged along a circumference of the annular backbone portion and defining a plurality of pockets for accommodating one or more rolling elements of the ball bearing,
• wherein each of the plurality of cantilever portions comprises:
• two prong portions;
• and
• a connection portion between the two prong portions;
• wherein a plurality of recesses are formed in a radially outer side of the cantilever portions,
• each one of the plurality of recesses is defined by the connection portion recessed from the associated two prong portions,
• each one of the plurality of recesses is open from the axially forward side of the bearing cage, and
• V1/V2≥5%,
• wherein V1 is a volume of the recess and V2 is a volume of the bearing cage.

A ball bearing, comprising:

• an inner ring comprising a raceway;
• an outer ring;
• a plurality of rolling elements disposed between the inner ring and the outer ring, wherein the plurality of rolling elements are received by the raceway of the inner ring;
• and
• a bearing cage positioned between the inner ring and the outer ring, wherein each of the plurality of rolling elements is received in one of the plurality of pockets, the bearing cage comprising:
• an annular backbone portion comprises a front side and an opposite back side;
• and
• a plurality of cantilever portions extending from the front side of the backbone portion in an axially forward direction of the bearing cage, the plurality of cantilever portions arranged along a circumference of the annular backbone portion and defining a plurality of pockets for accommodating the plurality of rolling elements of the ball bearing,
• wherein each of the plurality of cantilever portions comprises:
• two prong portions;
• a connection portion between the two prong portions;
• and
• a plurality of grooves formed in the radially inner side of the bearing cage;
• wherein the backbone portion comprises a radial thickness larger than a radial thickness of the plurality of cantilever portions;
• and
• wherein the inner ring further comprises:
• at least one circumferential groove in an outer diameter surface of the inner ring,
• wherein one of the at least one circumferential grooves at least partially overlaps with the plurality of grooves of the bearing cage in an axial direction of the ball bearing, and
• L6≥0.2 mm,
• wherein L6 is an axial width of the one of the at least one circumferential groove at least partially overlapping with the plurality of grooves of the bearing cage.

A ball bearing, comprising:

• an inner ring comprising a raceway;
• an outer ring;
• a plurality of rolling elements disposed between in the inner ring and the outer ring, wherein the plurality of rolling elements are received by the raceway of the inner ring;
• and
• a bearing cage positioned between the inner ring and the outer ring, wherein each of the plurality of rolling elements is received in one of the plurality of pockets, the bearing cage comprising:
• an annular backbone portion comprises a front side and an opposite back side;
• and
• a plurality of cantilever portions extending from the front side of the backbone portion in an axially forward direction of the bearing cage, the plurality of cantilever portions arranged along a circumference of the annular backbone portion and defining a plurality of pockets for accommodating the plurality of rolling elements of the ball bearing,
• wherein each of the plurality of cantilever portions comprises:
• two prong portions;
• a connection portion between the two prong portions;
• and
• a plurality of grooves formed in the radially inner side of the bearing cage,
• wherein the backbone portion comprises a radial thickness larger than a radial thickness of the plurality of cantilever portions, and
• a portion of the groove of the bearing cage extends over the raceway of the inner ring and comprises an axial dimension of L3, wherein
• L3≥0.05 mm.